This invention relates broadly to systems for storing and inflating life rafts and more particularly to hoses for extending between pressurized vessels and inflatable life rafts in such systems.
Some life raft storage systems are comprised of clamshell canisters designed to hold, for example, 24-man life rafts with provisions for survival at sea in an event of an emergency. Such life rafts are inflated by means of compressed-air cylinders which are also encased in the clamshell canisters. Compressed air is released from the cylinders into the rafts when lanyards, that are respectively attached to valves of the cylinders, are pulled. In a prior-art example, as is disclosed in U.S. Pat. No. 5,154,653 to Ketterman and Kinne for example, such a lanyard is attached to an inner-end portion of a 100-foot coiled rope, or rope bundle, which is encased in a "bung-plug" assembly located at one end of the clamshell canister, with an outer-end portion of the coiled rope being attached to a tie cleat on a boat. When an emergency occurs, for example when a boat on which a clamshell canister is mounted is sinking, the clamshell canister is thrown overboard along with the enclosed life raft and one or more compressed-air cylinders. The outer-end portion of the coiled rope is affixed to the boat. As the clamshell canister falls downwardly, toward the sea, the coiled rope is pulled out of the clamshell canister until the clamshell canister travels 100 feet from the tie cleat to which its outer-end portion is attached. At this point, the rope is placed under tension, and the lanyard is pulled, thereby opening the valve on the cylinder containing the compressed air to inflate the raft in the clamshell canister. As the raft inflates, it applies outwardly directed force on the clamshell canister, which separates top and bottom halves of the clamshell canister. This pressure on the top and bottom halves of the clamshell canister separates them and releases the life raft ready for use.
In recent years, two compressed-air cylinders have been included in the canisters so that the life rafts are more evenly inflated. In this regard, the nozzle of each of the cylinders is attached, via a hose assembly, to a separate inlet coupling that is fabricated into the side of the life raft. To satisfy space requirements within the canisters, the life rafts and compressed-air cylinders are stored in particular manners, with hoses therefrom extending to inlet couplings at two different locations on the life raft. It is necessary that these hoses withstand a great deal of internal pressure and that they be durable under adverse conditions. In this regard, these hoses must withstand pressure impulses of up to 6000 psi and pressures of up to 3000 PSI on a steady basis. In the past, such hose assemblies have been constructed of teflon or wire reinforced hose with a braided stainless steel cover and coupling fittings that are affixed to the ends of the hoses. In this respect, each of the coupling fittings on prior-art hoses have been comprised of a nipple which extends into the interior of the hose and a ferrule and collar that are affixed to the outer surface of the hose. At a gas-cylinder end of the hose, the fitting has been made as one piece with a cylinder-hose coupling having a female swivel nut mounted thereon by means of a circular retaining pin. As the swivel nut is turned, the nipple on the cylinder is pulled into engagement with the seat on the cylinder-hose coupling to form a metal-to-metal seal therewith. In order to prevent the metal-braid hose from damaging the inflatable life raft, a protective sleeve is shrunk about the outer surface thereof to cover most of the ferrules and all of the metallic braid.
A major disadvantage of this prior-art hose assembly used for life raft storage and inflation systems is that it is unduly expensive to construct. Thus, it is an object of this invention to provide a hose assembly for a life raft storage and inflation system which can be constructed less expensively.
A related disadvantage of the above-described hose assembly for life raft and storage systems is that its hose, ferrules, nipples, and couplings cannot be disassembled and therefore cannot be replaced individually. Thus, if one of these elements becomes defective, it is necessary to totally replace the hose assembly, even though the other elements thereof may still operate properly. Thus, it is an object of this invention to provide a life raft storage and inflation system that has a hose assembly with various parts that can be individually replaced and which can be repaired without replacing the entire assembly.
Another difficulty with prior-art hose assemblies for life raft storage and inflation systems is that they require undue amounts of metal-to-metal contact, which, in turn, promotes corrosion. For this reason, it has been necessary to replace the entire prior-art assemblies approximately every four years. The labor involved and the cost of the hoses makes this a very expensive procedure. Thus, it is a further object of this invention to provide a hose assembly for life raft storage and inflation systems which need not be replaced as often, and which can be refurbished without total replacement thereof.